Steam separator



1929 w. ALEXANDER 1,703,917

' STEAM SEPARATOR Filed May 20, 1927 I 1 Z1 .9 g a 16 r Parmesan. s, 1929.

WILLIAM ALEXANDER, OF GLASGOW, SCOTLAND.

STEAM SEPARATOR.

Application filed In 20, 1927, Serial No. 192,905, and in Great Britain lune 17, 1988.

ratus of the type and for the purpose 1ndicated; the term steam outlet is intended to 1y to the outlet pipe or passage for disc arglng purlfied steam, vapour, or gas from the separator; and the term drain outlet is intended to apply to the discharge opening of separating chamber for conveying away separated liquid or solid matter. I It is also intended that where the term steam is employed this term is to apply to and cover vapours and gases, and where the term li uid is employed this is intended to apply to iquids and solids either held insuspension or separated as the case may be.

The improvements have .for their objects the production of a strong stream-line vortex in the steam entering separating chamber, the maximum conservation of the velocit of the vortex throughout the separating c amber, especially of the core or central ortion of vortex, which portion is the most e ective, the prevention as far as possible of eddies in the stream line of the vortex, the provision of easy automaticdraina e of liquid by making use of the action of 0th centrifugal force and gravity whether the separator be disposed with its axis either vertical or horizontal, and the provision of such a shape in the ends of separator as to give great strength for a given thlckness.

To effect the stated objects of the invention the separator is characterized by having convergent guide passages for the ingoin steam, that is passages the. cross section 0 which diminishes as their outlet is approached the passages being of the kind known in tur ine practice as the parallel flow type, that is passages in which the steam has a component of velocity parallel to the axis; by" dispensing with any hollow or concavity, next separating 'chamber in the concentrically situated plate at the steam admission end of the separating chamber; by dispensing with any baflles or.

obstructions between the outlet of the guide passages and the steam outlet; and by arranging that the internal circular surfaces of separating chamber, and the end surface of this chamber next the outlet drain are sloped so that both gravity and centrifugal force have components along these sloping surfaces which components act towards the drain outlet.

The objects and nature of the invention being as set forth, and so that the invention may be easily understood, reference will now be made to the accompanying drawings which show three constructions respectively suitable for different applications.

Fig. 1 is a sectional view of separator suitable for connecting to a steam main.

Fi 2 is a sectional view of a separator suita Is for location in the steam space of a boiler and for connecting to the steam outlet pipe of boiler.

Fig. 3 is a sectional view of a separator suitable for applicationto an evaporator;

Figs. 4 and 5 show sections of vanes of alternative shapes, the section being taken at the cylindrical surface SS Fig. 1.

In Figs. 1, 2 and3 the steam inlet is at 3 and- 4 is the steam outlet. The guide passages 5 are of the parallel flow type, that is the steam passing through them has a component of velocity parallel to the axis of separator, and have their "sides 6 and 7 converging towards each other so as to give convergent flow of steam. The guide vanes 8 may have flat surfaces and be of uniform thickness as shown, in Fig. 4, or may have varying thickness and have any curvature as in Fig. 5 with the object of increasing the rate of convergence of the guide passa 'When the vanes are thus curved or vary in thickness the desired convergence of the guide passages may be obtained without sides 6 and 7 convergin towards each other. The side 6 ispart 0 a circular extension of the surface of the separating chamber and the side 7 is part of the cylindrical or conical surface of the end plate 20 .at the admission end of the separatmg chamber. The drain outlet is shown at 13, and the end 10 of separator at drain outlet end has an inward slope or inward conical form. The plate 20 has no concavity or hollow but is either flat or convex towards interior of separatin chamber.

In the horizonta lly disposed separator shown in Fig. 1 the separating chamber 9 has sides 11 the cross sectional diameter of which increases as the drain outlet is approached. In the vertically disposed separators shown in Figs. 2 and 3 the diameter ofthe cross section of separating chamber may be constant or may be varied in any manner desired. If the separator in Fig. 2 is fitted in a horizontal position, instead of vertically, then the cross section would preferably increase as shown in Fig. 2 and in Fig. 1.

In Fig. 1 the steam inlet branch 12 and the steam outlet branch 14 are provided to enable the separator to be connected in a pipe line. The steam inlet branch opens into an admission chamber 15 of larger diameter and having sloping or conical end surface 16. This form of separator, either with the inlet branch piece present or removed, is also suitable for fixing in the steam space of a boiler, the steam being led away through the boiler shell by a pipe bend connected to the stea outlet branch 14.

In Fig. 2 the steam outlet 4 is at the same end of separator as the steam inlet. This provision enables the separator to be fitted vertically in a boiler with the guide vanes situated in the uppermost and dryest zone of the steam space and at the same time enables a bent outlet pipe, leading the steam from separator to opening 18 in boiler shell 19, to be dispensed with. The bellinouthed secondary lip 21 at the entrance to the steam outlet pipe is provided for collecting any liquid that may run down the outside of the bellmouth. When liquid collects sufficiently it drops ofi into the vortex of steam and is thrown out against the sides of separating chamber instead of being dragging through the steam outlet pipe by entraining action in the case where the bellmouth is dispensed with: This secondary lip may or may not be provided as desired in all of the constructions shown. It will be noticed in the construction shown in Fig. 2 that the steam passes through the guide passages in a downward direction.

In Fig. 3, 22 is a part of the casing of an evaporator, and 23 is the outlet branch forthe steam. The steam passes in an upward direction through the ide passage. Both drain outlet end 10 an the steam outlet end 24 of separating chamber are sloped or .coned the former end inwardly. The diameter of separating chamber may be constant as shown or may increase as the drain outlet end is approached.

One advantage of converging the guide passages is that more perfect stream line motion of steam through them is induced, the formation of eddies is prevented, and any eddies present in the ingoing steam are smoothed out into the stream lines of general flow," so that a strong stream line vortex is induced in the separating chamber. Another advantage is that there is less pressure head lost for a given velocity generated during the flow through the guide passages.

The type of vortex formed is the natural whirlpool type in which the velocity of any particle of steam increases towards the axis at a rate approximately inversely as the distance of a particle of steam from the axis. It follows that the stream lines of the vortex are also convergent, and that the central part of the vortex has a far reater centrifugal force per pound of rotating substance than the outer portions, and for this reason, for higher separating effect, it is aimed in the present invention not to lessen but to augment the rate of convergence of stream lines beyond that given by the convergence of sides 6 and 7 of guide passages. This is provided for by so slopin or coning or giving convexity to one or both ends of the separating chamber that the cylindrical section of the steam space contained in chamber, the section being concentric with axis of chamber, diminishes as the axis of chamber is approached. The augmenting of convergence also involves dispensing with any concavity in plate 20 referred to above, and rather this plate.

In the separators referred to having the sides and drain outlet end both slo in as described, whether the axis be either orizontal or vertical, centrifugal force and gravity have components along the sloping surfaces referred to and cause separated liquid to find its way easily to the drain outlet.

When the separators described are used in the vertical position and the sides of the separating chamber are also vertical then the centrifugal force has no component along the surface towards the drain outlet, but gravity acts as already explained. Even if the separator is standing idle the sloping or vertical surfaces referred to, as the case may be, in virtue of gravity acting along the surfaces towards the drain outlet, again promote easy drainage, this being an advantage, as there may be otherwise an accumulatlon of condensed steam although there may be very little flow of steam through the separator at the time.

Again, the sides and drain outlet end of separating chamber sloping in the way described, form between them a deep annular V shaped groove of maximum diameter for the catchment of separated liquid.

The liquid has a rotational motion round the axis of the se arator, which motion, in vir tue of the large ydraulicinean depth of the groove, is conserved and gives rise to a correspondingly large velocity head and centrifugal force in the li uid which is thus ensured being efi'ectively e ected through the drain out-let.

Further, the sloping or coned drain outlet end of the separating chamber has great strength for a given thickness.

What I claim as new and desire to secure by Letters Patent of the United States is:

giving flatness to 1. A steam separator comprising an unoba steam inlet and a steam outlet, said cham- 1 structedchamber having a steam inlet and a ber diverging toward said outlet, an end stezm outlet, an end plate adjacent said inlet plate at said inlet end, and vanes cooperating and vanes cooperating with said inlet plate therewith to form admission openings con to form a plurality of admission openings tinuously converging in-the direction of flow. continuously converging in the direction of In testimony whereof I have signed my 15 flow. name to this specification.

2. A steam separator of the vortex type comprising an'unobstructed chamber having WILLIAM ALEXANDER. 

